The concentration of polycyclic aromatic hydrocarbons in sewage sludge in relation to the amount and origin of purified sewage

The present study included an evaluation of the content of 16 PAH in sewage sludge produced in 15 sewage treatment plants in southeastern Poland. Besides determining PAH content, the influence of the amount and origin of the sewage purified in the PAH content was also evaluated. Possible PAH sources in sewage were also evaluated by the calculations of the mutual relations. The results obtained showed a clear differentiation in the content of polycyclic aromatic hydrocarbons. The content of the PAH sum ranged from 2039.9 to 36439.8 μg/kg. The predominant contribution of 3 and 4-ring PAHs was observed. A significant relation was only found in the case of properties of the sludge purified and the PAH content (-0.547, at P=0.05). Evaluating relations between individual PAHs, a statistically significant relation was observed between the sum of the PAHs determined and the content of fluoranthene, chrysene and benzo[b]fluoranthene.